Firstly, let me just tell you that this guide is meant to specifically ruin any future experiences you will have with the adv mode as it is. I have specifically held back posting this in the past (^{not that everything here is unknown anyway. It's all exploits, I have a hard time hearing about frequently.)} to prevent a whole year of misery. Now that the ToadyOne will be posting DF:2012 anytime soon now, here goes:

• You can locate a tile that supplies small rocks, pick up an infinite quantity, and repeatedly throw them at your feet to get Legendary at Throwing and Archery, which in turn helps you aim a bow/crossbow, and in turn increases your Focus, Willpower and a few other desirable attributes. Use this ability to knock the head off a bogeyman miles away.
• (NB: I haven't seen this anywhere. Not even directly reported as a bug yet.) You may purchase/find a bag, pick up sand, move somewhere that isn't a sand tile, drop it, and interact(^{Not sure if it's U or I} ) with the bag to pick up an absolutely massive amount of sand and drain whatever you want, like shields, from shops, which leads to the next exploit,
• You can equip an infinite amount of shields and weapons. This is a commonly known exploit. Frankly, this is pointless once you're a 100 Lengendary Fighting or Shield user. Just (r)emove the shield and you hold it in the "emptiest" hand. This is useful for a nearly guaranteed chance of never missing critical shots or blocking every move.
• To train Strength, Focus, Endurance and other fighting traits, equip at least 4 shields, stalk a wild deer animal, set Combat Mode to Stand Ground, move right next to the animal to get it hostile, wait a few turns until you're a Novice or Proficient at Shield Using, lie down on the ground and (Ctrl r)ecord a Macro and mash (Ctrl p)lay the speed of light. After you reach Legendary in Shield Using, seek hostile enemies in large groups, rinse and repeat. Warning: You can faint from exhaustion, therefore even a rabbit can make quick work of you. This is unlikely once you gain Super(race) Endurance.

Also,

• As an additional bonus, one can set Combat mode to Close Combat, make sure hands are occupied, so that you don't strangle your victim or otherwise, and just hold down the arrow key respective to the direction of your prey. 10 Legendary Wrestler in no time at all.
• To train an individual weapon, take one training weapon version of it, and proceed to beat up nearby encampments or Hydras with it.
• To train a range weapon, stand on a cliff with a wall one tile away on your level, shoot it repeatedly until you have no more ammo, go down one z-level, retrieve the ammunition, and repeat. This is rather pointless, since throwing small rocks are still mind-boggling OP.)

I suppose this is all that's necessary to equate hacking an immortal into the game without actually hacking the raws to do so. Now, go on, beardless dwarf, be an hero and massacre clowns, or turn against the pathetic world. You are impossible to destroy.

This is also why I always achieve Ages other than Myth, because my adventurer makes such a name, that, after starting a new Fortress, the Age immediately progresses to Heroes, or if I'm particularly sadistic, the Age of Death.